An Autonomous Programmable Actuator and Shape Reconfigurable Structures using Bistability and Shape Memory Polymers

TL;DR

This paper introduces a 3D printed autonomous actuator using shape memory polymers and bistability, enabling precise, sequential, and multi-state shape reconfiguration of structures driven by temperature changes, with load-bearing capabilities.

Contribution

It presents a novel programmable actuator combining shape memory polymers and bistability for autonomous, multi-state structural deployment and reconfiguration.

Findings

Successful sequential activation of the actuator units.

Transformation of flat surfaces into complex 3D shapes.

Demonstrated load-bearing capacity during and after activation.

Abstract

Autonomous deployment and shape reconfiguration of structures is a crucial field of research in space exploration with emerging applications in the automotive, building and biomedical industries. Challenges in achieving autonomy include: bulky energy sources, imprecise deployment, jamming of components and lack of structural integrity. Leveraging advances in the fields of shape memory polymers, bistability and 3D multi-material printing, we present a 3D printed programmable actuator that enables the autonomous deployment and shape reconfiguration of structures activated though surrounding temperature change. Using a shape memory polymer as the temperature controllable energy source and a bistable mechanism as the linear actuator and force amplifier, the structures achieve precise geometric activation and quantifiable load bearing capacity. The proposed unit actuator integrates these two components and is designed to be assembled into larger deployable and shape reconfigurable structures. First, we demonstrate that the activation of the unit actuator can be sequenced by tailoring each shape memory polymer to a different activation time. Next, by changing the configuration of the actuator, we demonstrate an initially flat surface that transforms into a pyramid or a hyperbolic paraboloid, thus demonstrating a multi-state structure. Load bearing capability is demonstrated for both during activation and in the operating state.